76 - 100 of 649
Number of results to display per page
CreatorTitleDescriptionSubjectDate
76 Olivera, Baldomero M.; McIntosh, J. Michael; Gray, William Robertγ-Carboxyglutamate in a neuroactive toxinThe venom of a fish-hunting cone snail (Conus geographus) contains a novel toxin, the "sleeper" peptide, which induces a sleep-like state in mice when injected intracerebrally. We demonstrate that this peptide contains 5 mol of γ-carboxyglutamate (Gla) in 17 amino acids. The amino acid sequence o...Conus geographus; Venom; Conotoxins; gamma-Carboxyglutamate; Neurotoxins1984
77 Davidson, Diane W.Dispersal adaptations of some acacia species in the Australian arid zoneMost Australian representatives of the genus Acacia have diaspores with arillate appendages indicative of adaptation for active dispersal by animals. Based on physical and chemical characteristics of these arils and mechanisms of diaspore presentation, a number of arid zone acacias can be distingu...Acacia; Australian arid zone; Dispersal ecology; Fruit quality; Myrmecochory; Ornithochory; Seed parasitoids; Soil nutrients1984
78 Blair, David F.Electron spin relaxation of CuA and cytochrome a in cytochrome c oxidase: comparison to heme, copper, and sulfur radical complexesThe method of continuous saturation has been used to measure the electron spin relaxation parameter T1T2 at temperatures between 10 and 50 K for a variety of S = % species including: CuA and cytochrome a of cytochrome c oxidase, the type1 copper in several blue copper proteins, the type 2 coppe...Electron spin relaxation; EPR signals; Sulfur radical complexes1984
79 Rogers, Alan R.Sociobiology of sex and sexes (comment)A comment on "Sociobiology of sex and sexes" by Marion Blute.Sociobiology; Sex and sexes1984-04
80 Capecchi, Mario R.Synthesis of an ochre suppressor tRNA gene and expression in mammalian cells.We have used site-specific mutagenesis to change the anticodon of a Xenopus laevis tyrosine tRNA gene so that it would recognize ochre codons. This tRNA gene is expressed when amplified in monkey cells as part of a SV40 recombinant and efficiently suppresses termination at both the ochre codon separ...Xenopus; Nucleic Acid Conformation; Kidney; DNA Restriction Enzymes1984-11
81 Davidson, Diane W.Granivory in the Chihuahuan Desert: interactions within and between trophic levelsWe investigated the effects of Chihuahuan Desert granivores on three seasonal classes of plant resource species, the effects of these resource classes on one another, and the ways in which interactions through plant resources affect the abundances of seed consumers. At our study site, three seasona...Annual plant; Ant; Competition; Community; Desert; Ecosystem structure; Experiment; Granivore; Indirect interaction; Rodent; Population cycles; Seed predation1985
82 Davidson, Diane W.Experimental study of diffuse competition in harvester antsExperiments carried out over a 5-yr period in the Chihuahuan Desert support the a priori prediction of diffuse competition between two species of harvester ants. Despite dietary overlap between a large species {Pogonomyrmex rugosus) and a small species (Pheidole xerophila), the large species facilit...Chihuahuan Desert; Ants; Facilitation; Resource allocation; Granivory1985
83 Clayton, Dale H.Nocturnal foraging of yellow-crowned night herons in the BahamasDetailed observations of nocturnal foraging of the Yellow-crowned Night Heron (Nycticorax violacevs) are not to be found in the literature, though this species commonly feeds at night (Kushlan 1978, Riegner 1982a). I observed several Yellow-crowned Night Herons foraging during November and December...Nocturnal foraging; Bahamas; Nycticorax violacevs1985
84 Davidson, Diane W.Granivory in the Chihuahuan desert: interactions within and between trophic levelsWe investigated the effects of Chihuahuan Desert granivores on three seasonal classes of plant resource species, the effects of these resource classes on one another, and the ways in which interactions through plant resources affect the abundances of seed consumers. At our study site, three seasona...Annual plant; Ant; Competition; Community; Desert; Ecosystem structure; Experiment; Granivore; Indirect interaction; Rodent; Population cycles; Seed predation1985
85 Olivera, Baldomero M.; Gray, William Robert; Yoshikami, DojuConus geographus toxins that discriminate between neuronal and muscle sodium channelsWe describe the properties of a family of 22-amino acid peptides, the μ-conotoxins, which are useful probes for investigating voltage-dependent sodium channels of excitable tissues. The μ-conotoxins are present in the venom of the piscivorous marine snail, Conus geographus L. We have purified even...Conus geographus; Venom; Conotoxins; Sodium channels; Neurotoxins1985
86 Seger, JonIntraspecific resource competition as a cause of sympatric speciation[In most models of speciation], the fitness value of an animal is determined by the genotype it has, and the habitat in which it lives. In a more realistic model it should also depend on how much necessary resource is available for the animal and the competition from other genotypes for this resourc...Phenotype; Models; Species1985
87 Thomas, Kirk R.; Capecchi, Mario R.Nonreciprocal exchanges of information between DNA duplexes coinjected into mammalian. cell nucleiWe have examined the mechanism of homologous recombination between plasmid molecules coinjected into cultured mammalian cells. Cell lines containing recombinant DNA molecules were obtained by selecting for the reconstruction of a functional Neor gene from two plasmids that bear different amber mutat...Animals; Cells, Cultured; DNA Restriction Enzymes; Kinetics1985-01
88 Thomas, Kirk R.; Capecchi, Mario R.Efficient correction of mismatched bases in plasmid heteroduplexes injected into cultured mammalian cell nuclei.Heteroduplexes were prepared from two plasmids, pRH4-14/TK and pRH5-8/TK, containing different amber mutations in the neomycin resistance gene (Neor). The Neor gene was engineered to be expressed in both bacterial and mammalian cells. A functional Neor gene conferred kanamycin resistance to bacteria...Cell Nucleus; Cells, Cultured; Microinjections1985-01
89 Capecchi, Mario R.Expression of a microinjected porcine class I major histocompatibility complex gene in transgenic mice.A porcine class I major histocompatibility complex (SLA) gene has been introduced into the genome of a C57BL/10 mouse. This transgenic mouse expressed SLA antigen on its cell surfaces and transmitted the gene to offspring, in which the gene is also expressed. Skin grafts of such transgenic mice were...Genetic Engineering; Graft Rejection; Mice, Inbred C57BL1985-05-03
90 Clayton, Dale H.Neotropical tineidae, II: biological notes and descriptions of two new moths phoretic on spiny pocket mice in Costa Rica (Lepidoptera: Tineoidea)Two new species of tineid moths discovered riding on the backs of two species of spiny pocket mice (Heteromyidae) in Costa Rica are described. Amydria selvae, new species, was found on Heteromys desmarestianus Gray in the rainforest at Finca La Selva and Ptilopsaltis santarosae, new species, occurr...Neotropical Tineidae; Phoretic moths; Amydria selvae; Heteromys desmarestianus; Ptilopsaltis santarosae; Liomys salvini; Mouse moths1986
91 Beckerle, Mary C.Identification of a new protein localized at sites of cell-substrate adhesionA new protein found at sites of cellsubstrate adhesion has been identified by analysis of a nonimmune rabbit serum. By indirect immunofluorescence this serum stains focal contacts (adhesion plaques) and the associated termini of actin filament bundles in cultured chicken cells.Actin; Nonimmune rabbit serum; Polypeptide1986
92 Seger, JonIdeas in ecologyThe word "ecology" means different things to different people. For example, during the last 25 years or so the word has been used to label attitudes, life-styles, consumer goods, political parties, and college courses. In the 1960s one university renamed its "Home Economics" course "Home Ecology."...Behavioral ecology; Population ecology1986
93 Blair, David F.Chemical and spectroscopic evidence for the formation of a ferryl Fea3 intermediate during turnover of cytochrome c oxidaseWhen partially reduced cytochrome c oxidase samples are reoxidized with dioxygen, an EPR-silent dioxygen intermediate, which is at the three-electron level of dioxygen reduction, is trapped at the dioxygen reduction site. The intermediate has novel spectral features at 580 and 537 nm. Combined op...Cytochrome c oxidase; EPR; Fea3 intermediate; Reduction1986
94 Jorgensen, ErikMultiple transcripts from the Antennapedia gene of Drosophila melanogasterThe structures of four major transcripts from the homeotic gene Antennapedia of Drosophila melanogaster were determined. These transcripts constitute two RNA classes, each class initiating from a unique promoter but sharing 3' exons. Within the shared sequences is a major open reading frame encoding...Mutations; Sequences ; RNA1986
95 Bastiani, MichaelGuidance of neuronal growth cones in the grasshopper embryo. I. Recognition of a specific axonal pathway by the pCC neuronThe selective affinities that growth cones display for specific axonal surfaces give rise to stereotyped patterns of selective fasciculation. Previous studies on cell recognition by neuronal growth cones in the grasshopper embryo led to the proposal and initial experimental testing of the labeled-p...Fascicle; Axon; Affinity1986
96 Bastiani, MichaelGuidance of neuronal growth cones in the grasshopper embryo. II. Recognition of a specific axonal pathway by the aCC neuronIn the previous paper, we experimentally analyzed the selective affinity of the pCC growth cone for the MP1/dMP2 fascicle in the grasshopper embryo. Here we describe a similar experimental analysis demonstrating the selective affinity of the aCC growth cone for the U fascicle. These results support...Axon; Cell; Fascicle1986
97 Capecchi, Mario R.; Thomas, Kirk R.High frequency targeting of genes to specific sites in the mammalian genomeWe corrected a defective gene residing in the chromosome of a mammalian cell by injecting into the nucleus copies of the same gene carrying a different mutation. We determined how the number, the arrangement, and the chromosomal position of the integrated gene, as well as the number of injected mo...Homologous recombination; Mutant genes; Mammalian genome1986
98 Bastiani, MichaelGuidance of neuronal growth cones in the grasshopper embryo. III. Recognition of specific glial pathwaysIn the previous 2 papers, we focused on the selective affinities that growth cones display for specific axonal pathways. Little is known, however, about how this orthogonal scaffold of axonal pathways in the CNS is established in the first place, and what, if any, role glia might play in these even...CNS; Nerve; Cells1986
99 Olivera, Baldomero M.Calcium channel antagonists: ω-conotoxin defines a new high affinity siteThe ω-conotoxins, a class of Ca2+ channel antagonists from fish-hunting marine snails, have recently been described (Olivera, B. M., McIntosh, J. M., Zeikus, R., Gray, W. R., Varga, J., Rivier, J., de Santos, V., and Cruz, L. J. (1985) Science, 230, 1338-1343). One of these peptide neurotoxins...Conotoxins; Calcium channels; Synaptosomes; Neurotoxins1986
100 Bastiani, MichaelGuidance of neuronal growth cones in the grasshopper embryo. IV. Temporal delay experimentsIn the previous 3 papers, we demonstrated that neuronal growth cones display selective affinities for both specific axonal and glial pathways in the grasshopper embryo; for example, the pCC growth cone selectively recognizes the MPl/dMP2 axons, while the aCC growth cone selectively recognizes the U...Pathways; Neurons; Axons1986
76 - 100 of 649